Cooling, shorter days
Succulent harvest abounds
Prepare now for cold
Harvesting the fruits of all that labor and preparing for winter keep the September gardener busy. Deadheading, clearing away debris, and composting spent annuals all help to prevent future problems with pests and diseases.
Many apple varieties are ready for harvest (assuming the birds have left any uneaten). Other apple varieties will need some colder weather to sweeten. If you notice small brown, corky areas under the skin, it is called bitter pit. Bitter pit, like blossom end rot in tomatoes, is caused by a calcium deficiency early in the spring. In this case, however, the condition can be treated on future crops by spraying the leaves with calcium nitrate just after bloom and again one or two months later. Use one tablespoon per gallon of water.
Carrots prefer loose soil, but shorter varieties perform well enough in our heavy clay. The addition of compost can help aerate the soil and provide valuable nutrients. Carrots should be planted no more than 1/2” deep and plants should be thinned to 3” apart, to avoid forking and twisting. Water regularly but allow some drying to prevent cracking. Successive plantings provides an ongoing harvest. Carrots can be planted between landscape perennials for productive use of space.
Areas of the garden that will be left bare over the winter are better planted with cover crops. Cover crops help maintain important soil microorganisms that will, in turn, support your spring and summer crops next year. Fava beans are an excellent choice in the Bay Area.
If rose leaves are exhibiting neat round or oval holes in them, it is probably the beneficial leaf cutter bee and should be ignored. The sections of leaf are used to line brood cells, which are also filled with nectar and pollen.
Squash and cucumber plants are susceptible to a disease carried by aphids and cucumber beetles. Mosaic virus causes leaves to become mottled and stunts plant growth. Fruit may become white. Diseased plants should be removed and put in the trash. Do not add to the compost pile.
As nights become cooler, it is common for powdery mildew to strike. Affected leaves should be removed and thrown in the trash, and overhead watering should be avoided.
Gnawed fruit, empty snail shells, and tiny black pellets are all signs of roof rats. These pests can infiltrate your attic, crawl space, garage, storage shed, and trees. Rat traps are an excellent way to remove resident rats. Keeping pet and livestock food sealed up and harvesting crops as soon as possible will help make your yard less desirable to the local rat population. Since rats can carry serious diseases and damage electrical wiring, it is worth the effort to get rid of rats.
If leaf stippling and tiny webs are seen, spider mites are probably the reason. Spider mites prefer dusty conditions, so spraying infested plants with the hose can help. Using broad spectrum pesticides is not recommended because they will kill the spider mites’ natural predators. Heavy spider mite infestations can be treated with insecticidal soap or horticultural oil.
Any yellow flowers produced by your tomatoes now will not have time to mature before temperatures cause fruit to turn mealy before maturing. Instead, remove those flowers to encourage plants to put all their energy into any fruit that is already on the vine.
September is the time to plant many winter crops, including artichoke, arugula, beets, bok choy, cabbage, carrots, cauliflower, chard, cilantro, collards, dill, fennel, kale, leeks, parsnips, peas, radishes, rutabagas, spinach, and turnips.
Enjoy the fruits of your labor!
Longer days of sun
Burst forth fruits and leaves
June is a busy month in the garden. Summer heat means irrigation and ants seem to be everywhere. Fruits, flowers, and mulch are the name of the game when it comes to June garden chores.
Ants & aphids
The bane of all gardeners, aphids are in full force in June. You may see ant trails in trees or curled leaves. Ants and aphids have a mutually beneficial relationship that may not kill garden plants, but they can carry diseases that will. They can also make fruit and vegetables inedible. Monitor for ants and aphids at least twice a week. If ant trails are seen, wrap tree trunks with tape and apply sticky barriers. This sticky goo will prevent ants form protecting and farming the aphids and halt the spread of many diseases. Aphid populations can then be reduced with a powerful spray from the hose. Adding plants that attract beneficial insects will also curb aphid populations.
Armored scale are parasites that suck the living sap from shrubs and trees. In June, these difficult to control pests are in a crawler stage that is easier to defeat. Monitor plants for armored scale infestations. Apply horticultural oil (not dormant oil) every month in summer to affected plants.
Bees are out in force, collecting pollen and nectar for their families (and pollinating nearly all of our garden crops). If you see a swarm, know that swarming bees are generally not aggressive or a threat, they are simply looking for a new home. You call contact your local Bee Guild or Master Gardeners for information on swarm collection. Honey bees continue to struggle and research on colony collapse disorder is ongoing. Recent findings have shown that systemic pesticides made with neonicotinoids are adding to the threat against native bees, but not honey bees. You can do your part to help our pollinators (and protect our honey supply) by avoiding the use of insecticides and pesticides when bees are present.
Blossom end rot
Are there brown depressions on the bottom of your tomatoes? This is caused by not enough calcium or irregular watering. Since most soils have adequate calcium, watering is usually the culprit. Without regular watering, the calcium in the soil cannot reach the plant. Mulching can help. Water tomatoes regularly, allowing the soil to dry out between waterings.
Blackened twigs & branches
If twigs and branches are turning dark or burnt looking, you have a problem. Generally, the damage starts at the tips and moves toward the body of the plant. This can either be dieback or fireblight. In either case, all you can do is remove the damaged tissue, cutting well below the visible infection and cleaning your clippers with disinfectant between each cut. Take a close look at the cut to make sure healthy tissue is visible. To reduce the chance of these fungal diseases attacking fruit trees in June, reduce or halt watering during the bloom and avoid adding nitrogen. Nitrogen stimulates new growth that is especially vulnerable to infection.
In California, most soils contain adequate nutrients for citrus growth, except nitrogen. One-year old trees will need 1/10 of a pound of nitrogen, while mature trees need approximately 1-1/2 pounds. These amounts should be divided into three different feedings in April, June and August. Blood meal is an excellent source of nitrogen, without all the fillers, or you can purchase a balanced product that contains zinc. Spread the fertilizer evenly over the entire root area and water in.
QUARANTINE WARNING: MOST OF SANTA CLARA COUNTY IS UNDER QUARANTINE FOR CITRUS, DUE TO THE ASIAN CITRUS PSYLLID. CHECK THIS MAP TO SEE IF YOU ARE AFFECTED.
Container planting is an excellent way to garden in small spaces and to add art and color to the landscape. However, June’s high temperatures can dry out containers very rapidly. To make matters worse, frequent irrigation can also leach out nutrients. It’s a dilemma. Gardeners can reduce these problems by using glazed clay pots, which dry out slower than unglazed pots. Dark plastic should also be avoided because it can get too hot and cook the roots. Good drainage is important, but you can help container plants hang on to water and nutrients by using potting soil, rather than planting mix. Also, be sure to get those pots off hot concrete. By creating even a little air space under the pots, you can help them stay cool.
June usually provides an abundance of fruit. If damaged fruit is seen, take a closer look. If the fruit looks chewed on, it’s probably rats or squirrels. Personally, I use Bobbex-R to deter these destructive, disease-carrying pests. My dogs enjoy helping out, too! I also use traps to kill rats. It’s a bit disgusting, but it works.
Does the fruit show stab marks? That’s usually birds. The only way to keep birds out of fruit trees is with netting or a tree cage. The netting is a royal pain to put up and take down, but it’s surprisingly easy to build a permanent tree cage. Most birds will only take a bite or two out of dozens of fruits, ruining a crop. Netting placed directly on the plant does not protect fruit near the netting. I also discourage birds by hanging old CDs in my fruit trees and mounting shiny pinwheels in various places. Breezes cause them to spin and reflect light, which seems to alarm the birds some of the time..
Spent ornamental flowers should be removed to stimulate new growth. When deadheading, don’t clip just below the flower. Instead, look down the stem for a leaf connection that shows bud growth. June deadheading is also a good time to prune for improved shape, structure and air flow.
Another common pest, earwigs are second only to slugs and snails in garden destruction. Even though they eat aphids, the damage they cause doesn’t balance out. Trap earwigs in moist, tightly rolled newspaper or cardboard tubes. Earwigs will gather in these bundles after their nightly feeding and you can toss them in the trash in the morning.
Fruit drop and fruit thinning
Don't be concerned if your fruit trees suddenly drop a majority of their blossoms or immature fruits. This normal behavior, called June drop or blossom drop, prevents trees from producing more fruit than they can support. To help your trees create the highest quality and best sized fruit, this is the time to thin fruits.
If you haven’t already, June is a good time to check irrigation systems for leaks. Drip systems should be flushed and emitters checked for clogs. This is also a good time to test to see where, exactly, sprinklers are spraying and where they are not. There’s no sense in wasting precious water in urban drool and the spray should never hit tree trunks.
Mulching is one of the best things you can do in the garden, especially in June. Mulching stabilizes soil temperatures, reduces weeds, and helps the soil retain moisture. Aged compost, placed on top of the soil, is mulch. Tree trimmings make excellent mulch and they can be acquired for free from tree trimming companies! As mulch breaks down, it adds valuable nutrients to the soil and improves soil structure. Just make sure that mulch is kept away from tree trunks and that it isn’t too thick. Generally speaking, a layer of 3 inches is just right. Too much mulch can interfere with gas exchanges.
If you haven't started already, June is an excellent time to plant those heat loving peppers, squashes, eggplants, and melons. Also, you can create an ongoing harvest by succession planting radishes, beans, and other determinant crops.
As roses give us their lovely June blooms, they may also put out suckers. Most modern roses are actually grafted onto hardy root stock that will not produce those lovely flowers. If new growth is emerging from underground, rip them out. Desirable canes, on the other hand, will grow out of aboveground buds and should be allowed to grow (assuming they won’t result in crossed canes or poor air flow. Black spot, rust, and powdery mildew are common fungal diseases of roses. Proper pruning can reduce the chances of these diseases occurring. Diseased leaves should be removed and discarded.
Be sure to put on your sunscreen, wear a hat, and keep those tools clean and sharp as you enjoy the garden in June!
As busy as bees
We pierce the warming topsoil
With dreams of freshness
May is one of the busiest months in the garden. Temperatures have warmed enough for us to begin planting in earnest. Weeds, pests, and beneficial insects are out in force. And it's gorgeous outside!
Bees are very active in May. There is simply so much pollen and nectar to collect! Sometimes, a honey bee colony may swarm. If you see a swarm, don’t panic. As in any other time when working around bees, remain calm, move gently, and give them their space. Contact your local Master Gardeners to have swarms removed.
Bulbs & other flowers
If flowering bulbs were looking crowded during the recent bloom time, delay digging them up to separate until after all the foliage is completely dry. Bulbs pull important nutrients from these leaves to help start up again next spring. Bulbs that are dug up and separated can be replanted in a new location, gifted to friends, or stored in a cool, dry, dark location until fall. If you want fall blooms, plant now.
They are countless varieties of plants that perform well in containers. Do them all a favor in May and get them off that soon-to-be hot concrete patio. Creating even the smallest space under container plants can reduce the roasting effect, which means they will need less water. Speaking of water, warmer temperatures mean container plants will start drying out more quickly. Water as needed.
Many flowers are in full bloom in May. To encourage plants to continue creating blooms, remove spent flowers as soon as they are seen. This also reduces habitat for many pests and diseases. Pinch back borage, petunias, and fuchsias to prevent plants from becoming top heavy.
May is the time fireblight shows itself in the Bay Area. Fireblight is a bacterial disease that makes plants look as though they had been damaged by fire. It attacks apples, pear and quince, most often, but can also infect ornamentals, such as toyon and pyracantha. Very often, the growing tip folds over into a shepherd’s crook shape. Fireblight can kill a mature tree, so complete removal of any diseased tissue is critical. Dip clippers into a 1 part bleach, 9 parts water solution between each cut to prevent reinfection. The final cut should be 8-12 inches below the diseased area.
May should be the time when fruit trees are covered with immature fruits. Thin those fruits now or regret it later. Too much fruit in one place means none of them taste as good as they might have. It also creates habitat for pests and disease. Apples should be thinned to no more than 3 fruits to a cluster, or one fruit for every 6 inches of branch. Apricots and other stone fruits need 4-6” between fruits for optimal growth, flavor, and sweetness. Also, be sure to check apples for codling moth damage.
If you still have a lawn, be sure to water it as early in the morning as possible. That way, the water isn’t lost to evaporation and the grass has time to dry out during the day, reducing the chance of fungal diseases. For the most part, I use water from my washing machine to water my lawn and it has been working very well. Check the lawn for weeds such as spurge, burclover, and whatever happens to invade your neighborhood. When mowing, set the blade height as high as you are comfortable with in summer. Taller grass shades the soil. This reduces evaporation and it makes the soil more comfortable for valuable earthworms and microbes.
Mulch and compost
Compost and mulch are two of the best things to add to any landscape. They add valuable nutrients to the soil, improve soil structure, and stabilize soil temperature. In our heavy clay soil, mulch prevents the baked concrete look we have come to expect in summer. [An important note about soil additives - while it may sound right to add sand to clay soil, to reduce compaction, it ends up creating concrete. Don’t do it!]
Slugs & snails
Slugs and snails can devastate young May seedlings. Applying non-toxic slug and snail bait lightly around new planting areas can save the crop. While there are more effective baits, those made with iron phosphate are not toxic to pets and wildlife and I have found they work well enough.
This is the most welcome news of the season in the Bay Area. Nearly all summer growing plants (tomatoes, cucumbers, melons, squash, beans, corn, and peppers) can be put in the ground in May. If you are using transplants, be sure harden them off gradually or they may lose much of their vigor and productivity. Hardening-off simply means placing them outdoors in a protected location for a few hours. Slowly increase the time over a couple of weeks. Be sure to stake tomato plants now, while they are small. This can be done in tandem with quarantining new plants. And add straw under melon, squash, and strawberry plants to reduce fungal infection.
If verticillium wilt occurred last year, it is important to plant members of the nightshade family (tomatoes, potatoes, peppers and eggplant) someplace else. Verticillium wilt is a fungal disease that shows as yellowing older leaves, at first. Then, as the disease spreads, wilting occurs. Young plants nearly always die. Since the fungal spores can remain in the soil for 10-15 years, crop rotation is the best prevention.
California’s drought is continuing, despite the fair bit of rain we have received so far. The truth is, the Golden State has always been drought-prone and we would be wise to learn to live accordingly. When water restrictions were first implemented, I vowed to take meaningful steps to reduce our water consumption. As a result, we now use only 25% of the water we used to use! Surprisingly, my garden has not suffered and neither have we. These steps can help you conserve water while still caring for the garden:
Just as young garden plants are really kicking it into high gear in May, so are the weeds. Take my word for it, pulling them while they are small, and before the soil is baked, is much easier than later. Weeds take precious water and nutrients from garden plants. In most cases, the sooner they are gone, the better.
So, put on the hat and sunscreen and get out there in that May garden!